return NULL;
}
+/* Caller must have device mutex */
+static void __vhost_vq_attach_worker(struct vhost_virtqueue *vq,
+ struct vhost_worker *worker)
+{
+ if (vq->worker)
+ vq->worker->attachment_cnt--;
+ worker->attachment_cnt++;
+ vq->worker = worker;
+}
+
+ /* Caller must have device and virtqueue mutex */
+static int vhost_vq_attach_worker(struct vhost_virtqueue *vq,
+ struct vhost_vring_worker *info)
+{
+ unsigned long index = info->worker_id;
+ struct vhost_dev *dev = vq->dev;
+ struct vhost_worker *worker;
+
+ if (!dev->use_worker)
+ return -EINVAL;
+
+ /*
+ * We only allow userspace to set a virtqueue's worker if it's not
+ * active and polling is not enabled. We also assume drivers
+ * supporting this will not be internally queueing works directly or
+ * via calls like vhost_dev_flush at this time.
+ */
+ if (vhost_vq_get_backend(vq) || vq->kick)
+ return -EBUSY;
+
+ worker = xa_find(&dev->worker_xa, &index, UINT_MAX, XA_PRESENT);
+ if (!worker || worker->id != info->worker_id)
+ return -ENODEV;
+
+ __vhost_vq_attach_worker(vq, worker);
+ return 0;
+}
+
+/* Caller must have device mutex */
+static int vhost_new_worker(struct vhost_dev *dev,
+ struct vhost_worker_state *info)
+{
+ struct vhost_worker *worker;
+
+ worker = vhost_worker_create(dev);
+ if (!worker)
+ return -ENOMEM;
+
+ info->worker_id = worker->id;
+ return 0;
+}
+
+/* Caller must have device mutex */
+static int vhost_free_worker(struct vhost_dev *dev,
+ struct vhost_worker_state *info)
+{
+ unsigned long index = info->worker_id;
+ struct vhost_worker *worker;
+
+ worker = xa_find(&dev->worker_xa, &index, UINT_MAX, XA_PRESENT);
+ if (!worker || worker->id != info->worker_id)
+ return -ENODEV;
+
+ if (worker->attachment_cnt)
+ return -EBUSY;
+
+ vhost_worker_destroy(dev, worker);
+ return 0;
+}
+
static int vhost_get_vq_from_user(struct vhost_dev *dev, void __user *argp,
struct vhost_virtqueue **vq, u32 *id)
{
return 0;
}
+/* Caller must have device mutex */
+long vhost_worker_ioctl(struct vhost_dev *dev, unsigned int ioctl,
+ void __user *argp)
+{
+ struct vhost_vring_worker ring_worker;
+ struct vhost_worker_state state;
+ struct vhost_virtqueue *vq;
+ long ret;
+ u32 idx;
+
+ if (!dev->use_worker)
+ return -EINVAL;
+
+ if (!vhost_dev_has_owner(dev))
+ return -EINVAL;
+
+ ret = vhost_dev_check_owner(dev);
+ if (ret)
+ return ret;
+
+ switch (ioctl) {
+ /* dev worker ioctls */
+ case VHOST_NEW_WORKER:
+ ret = vhost_new_worker(dev, &state);
+ if (!ret && copy_to_user(argp, &state, sizeof(state)))
+ ret = -EFAULT;
+ return ret;
+ case VHOST_FREE_WORKER:
+ if (copy_from_user(&state, argp, sizeof(state)))
+ return -EFAULT;
+ return vhost_free_worker(dev, &state);
+ /* vring worker ioctls */
+ case VHOST_ATTACH_VRING_WORKER:
+ case VHOST_GET_VRING_WORKER:
+ break;
+ default:
+ return -ENOIOCTLCMD;
+ }
+
+ ret = vhost_get_vq_from_user(dev, argp, &vq, &idx);
+ if (ret)
+ return ret;
+
+ mutex_lock(&vq->mutex);
+ switch (ioctl) {
+ case VHOST_ATTACH_VRING_WORKER:
+ if (copy_from_user(&ring_worker, argp, sizeof(ring_worker))) {
+ ret = -EFAULT;
+ break;
+ }
+
+ ret = vhost_vq_attach_worker(vq, &ring_worker);
+ break;
+ case VHOST_GET_VRING_WORKER:
+ ring_worker.index = idx;
+ ring_worker.worker_id = vq->worker->id;
+
+ if (copy_to_user(argp, &ring_worker, sizeof(ring_worker)))
+ ret = -EFAULT;
+ break;
+ default:
+ ret = -ENOIOCTLCMD;
+ break;
+ }
+
+ mutex_unlock(&vq->mutex);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(vhost_worker_ioctl);
+
/* Caller should have device mutex */
long vhost_dev_set_owner(struct vhost_dev *dev)
{
smp_wmb();
for (i = 0; i < dev->nvqs; i++)
- dev->vqs[i]->worker = worker;
+ __vhost_vq_attach_worker(dev->vqs[i], worker);
}
return 0;
#define VHOST_SET_LOG_BASE _IOW(VHOST_VIRTIO, 0x04, __u64)
/* Specify an eventfd file descriptor to signal on log write. */
#define VHOST_SET_LOG_FD _IOW(VHOST_VIRTIO, 0x07, int)
+/* By default, a device gets one vhost_worker that its virtqueues share. This
+ * command allows the owner of the device to create an additional vhost_worker
+ * for the device. It can later be bound to 1 or more of its virtqueues using
+ * the VHOST_ATTACH_VRING_WORKER command.
+ *
+ * This must be called after VHOST_SET_OWNER and the caller must be the owner
+ * of the device. The new thread will inherit caller's cgroups and namespaces,
+ * and will share the caller's memory space. The new thread will also be
+ * counted against the caller's RLIMIT_NPROC value.
+ *
+ * The worker's ID used in other commands will be returned in
+ * vhost_worker_state.
+ */
+#define VHOST_NEW_WORKER _IOR(VHOST_VIRTIO, 0x8, struct vhost_worker_state)
+/* Free a worker created with VHOST_NEW_WORKER if it's not attached to any
+ * virtqueue. If userspace is not able to call this for workers its created,
+ * the kernel will free all the device's workers when the device is closed.
+ */
+#define VHOST_FREE_WORKER _IOW(VHOST_VIRTIO, 0x9, struct vhost_worker_state)
/* Ring setup. */
/* Set number of descriptors in ring. This parameter can not
#define VHOST_VRING_BIG_ENDIAN 1
#define VHOST_SET_VRING_ENDIAN _IOW(VHOST_VIRTIO, 0x13, struct vhost_vring_state)
#define VHOST_GET_VRING_ENDIAN _IOW(VHOST_VIRTIO, 0x14, struct vhost_vring_state)
+/* Attach a vhost_worker created with VHOST_NEW_WORKER to one of the device's
+ * virtqueues. This must be done before VHOST_SET_VRING_KICK and the driver
+ * specific ioctl to activate the virtqueue (VHOST_SCSI_SET_ENDPOINT,
+ * VHOST_NET_SET_BACKEND, VHOST_VSOCK_SET_RUNNING) has been run.
+ *
+ * This will replace the virtqueue's existing worker. If the replaced worker
+ * is no longer attached to any virtqueues, it can be freed with
+ * VHOST_FREE_WORKER.
+ */
+#define VHOST_ATTACH_VRING_WORKER _IOW(VHOST_VIRTIO, 0x15, \
+ struct vhost_vring_worker)
+/* Return the vring worker's ID */
+#define VHOST_GET_VRING_WORKER _IOWR(VHOST_VIRTIO, 0x16, \
+ struct vhost_vring_worker)
/* The following ioctls use eventfd file descriptors to signal and poll
* for events. */
projects / linux-block.git / commitdiff